[PATCH 0/3] lib: add "on" and "off" to strtobool

This consolidates logic for handling "on"/"off" parsing for bools into
the existing strtobool function. This requires making sure callers are
passing NULL-terminated strings.

-Kees

Some callers of strtobool were passing a pointer to unterminated strings.
This fixes the issue and consolidates some logic in cifs.

Signed-off-by: Kees Cook <redacted>
Cc: Amitkumar Karwar <redacted>
Cc: Nishant Sarmukadam <redacted>
Cc: Kalle Valo <redacted>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
---
 drivers/net/wireless/marvell/mwifiex/debugfs.c |   6 +-
 fs/cifs/cifs_debug.c                           | 106 ++++++++++++-------------
 fs/cifs/cifs_debug.h                           |   2 +-
 fs/cifs/cifsfs.c                               |   6 +-
 fs/cifs/cifsglob.h                             |   4 +-
 5 files changed, 58 insertions(+), 66 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/debugfs.c b/drivers/net/wireless/marvell/mwifiex/debugfs.c
index 0b9c580af988..76af60899c69 100644
--- a/drivers/net/wireless/marvell/mwifiex/debugfs.c
+++ b/drivers/net/wireless/marvell/mwifiex/debugfs.c

@@ -880,13 +880,13 @@ mwifiex_reset_write(struct file *file,
 {
 	struct mwifiex_private *priv = file->private_data;
 	struct mwifiex_adapter *adapter = priv->adapter;
-	char cmd;
+	char cmd[2] = { '\0' };
 	bool result;
 
-	if (copy_from_user(&cmd, ubuf, sizeof(cmd)))
+	if (copy_from_user(cmd, ubuf, sizeof(char)))
 		return -EFAULT;
 
-	if (strtobool(&cmd, &result))
+	if (strtobool(cmd, &result))
 		return -EINVAL;
 
 	if (!result)

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 50b268483302..2f7ffcc9e364 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c

@@ -251,11 +251,29 @@ static const struct file_operations cifs_debug_data_proc_fops = {
 	.release	= single_release,
 };
 
+static int get_user_bool(const char __user *buffer, bool *store)
+{
+	char c[2] = { '\0' };
+	bool bv;
+	int rc;
+
+	rc = get_user(c[0], buffer);
+	if (rc)
+		return rc;
+
+	rc = strtobool(c, &bv);
+	if (rc)
+		return rc;
+
+	*store = bv;
+
+	return 0;
+}
+
 #ifdef CONFIG_CIFS_STATS
 static ssize_t cifs_stats_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
 	bool bv;
 	int rc;
 	struct list_head *tmp1, *tmp2, *tmp3;

@@ -263,34 +281,32 @@ static ssize_t cifs_stats_proc_write(struct file *file,
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 
-	rc = get_user(c, buffer);
+	rc = get_user_bool(buffer, &bv);
 	if (rc)
 		return rc;
 
-	if (strtobool(&c, &bv) == 0) {
 #ifdef CONFIG_CIFS_STATS2
-		atomic_set(&totBufAllocCount, 0);
-		atomic_set(&totSmBufAllocCount, 0);
+	atomic_set(&totBufAllocCount, 0);
+	atomic_set(&totSmBufAllocCount, 0);
 #endif /* CONFIG_CIFS_STATS2 */
-		spin_lock(&cifs_tcp_ses_lock);
-		list_for_each(tmp1, &cifs_tcp_ses_list) {
-			server = list_entry(tmp1, struct TCP_Server_Info,
-					    tcp_ses_list);
-			list_for_each(tmp2, &server->smb_ses_list) {
-				ses = list_entry(tmp2, struct cifs_ses,
-						 smb_ses_list);
-				list_for_each(tmp3, &ses->tcon_list) {
-					tcon = list_entry(tmp3,
-							  struct cifs_tcon,
-							  tcon_list);
-					atomic_set(&tcon->num_smbs_sent, 0);
-					if (server->ops->clear_stats)
-						server->ops->clear_stats(tcon);
-				}
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each(tmp1, &cifs_tcp_ses_list) {
+		server = list_entry(tmp1, struct TCP_Server_Info,
+				    tcp_ses_list);
+		list_for_each(tmp2, &server->smb_ses_list) {
+			ses = list_entry(tmp2, struct cifs_ses,
+					 smb_ses_list);
+			list_for_each(tmp3, &ses->tcon_list) {
+				tcon = list_entry(tmp3,
+						  struct cifs_tcon,
+						  tcon_list);
+				atomic_set(&tcon->num_smbs_sent, 0);
+				if (server->ops->clear_stats)
+					server->ops->clear_stats(tcon);
 			}
 		}
-		spin_unlock(&cifs_tcp_ses_lock);
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	return count;
 }

@@ -433,17 +449,17 @@ static int cifsFYI_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
 		size_t count, loff_t *ppos)
 {
-	char c;
+	char c[2] = { '\0' };
 	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = get_user(c[0], buffer);
 	if (rc)
 		return rc;
-	if (strtobool(&c, &bv) == 0)
+	if (strtobool(c, &bv) == 0)
 		cifsFYI = bv;
-	else if ((c > '1') && (c <= '9'))
-		cifsFYI = (int) (c - '0'); /* see cifs_debug.h for meanings */
+	else if ((c[0] > '1') && (c[0] <= '9'))
+		cifsFYI = (int) (c[0] - '0'); /* see cifs_debug.h for meanings */
 
 	return count;
 }

@@ -471,20 +487,12 @@ static int cifs_linux_ext_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_linux_ext_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = get_user_bool(buffer, &linuxExtEnabled);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	linuxExtEnabled = bv;
-
 	return count;
 }
 

@@ -511,20 +519,12 @@ static int cifs_lookup_cache_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_lookup_cache_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = get_user_bool(buffer, &lookupCacheEnabled);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	lookupCacheEnabled = bv;
-
 	return count;
 }
 

@@ -551,20 +551,12 @@ static int traceSMB_proc_open(struct inode *inode, struct file *file)
 static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
 		size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = get_user_bool(buffer, &traceSMB);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	traceSMB = bv;
-
 	return count;
 }
 

@@ -622,7 +614,7 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
 	int rc;
 	unsigned int flags;
 	char flags_string[12];
-	char c;
+	char c[2] = { '\0' };
 	bool bv;
 
 	if ((count < 1) || (count > 11))

@@ -635,11 +627,11 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
 
 	if (count < 3) {
 		/* single char or single char followed by null */
-		c = flags_string[0];
-		if (strtobool(&c, &bv) == 0) {
+		c[0] = flags_string[0];
+		if (strtobool(c, &bv) == 0) {
 			global_secflags = bv ? CIFSSEC_MAX : CIFSSEC_DEF;
 			return count;
-		} else if (!isdigit(c)) {
+		} else if (!isdigit(c[0])) {
 			cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
 					flags_string);
 			return -EINVAL;

diff --git a/fs/cifs/cifs_debug.h b/fs/cifs/cifs_debug.h
index 66cf0f9fff89..c611ca2339d7 100644
--- a/fs/cifs/cifs_debug.h
+++ b/fs/cifs/cifs_debug.h

@@ -25,7 +25,7 @@
 void cifs_dump_mem(char *label, void *data, int length);
 void cifs_dump_detail(void *);
 void cifs_dump_mids(struct TCP_Server_Info *);
-extern int traceSMB;		/* flag which enables the function below */
+extern bool traceSMB;		/* flag which enables the function below */
 void dump_smb(void *, int);
 #define CIFS_INFO	0x01
 #define CIFS_RC		0x02

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index c48ca13673e3..931b446f2a44 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c

@@ -54,10 +54,10 @@
 #endif
 
 int cifsFYI = 0;
-int traceSMB = 0;
+bool traceSMB;
 bool enable_oplocks = true;
-unsigned int linuxExtEnabled = 1;
-unsigned int lookupCacheEnabled = 1;
+bool linuxExtEnabled = true;
+bool lookupCacheEnabled = true;
 unsigned int global_secflags = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a25b2513f146..d21da9f05bae 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h

@@ -1596,11 +1596,11 @@ GLOBAL_EXTERN atomic_t midCount;
 
 /* Misc globals */
 GLOBAL_EXTERN bool enable_oplocks; /* enable or disable oplocks */
-GLOBAL_EXTERN unsigned int lookupCacheEnabled;
+GLOBAL_EXTERN bool lookupCacheEnabled;
 GLOBAL_EXTERN unsigned int global_secflags;	/* if on, session setup sent
 				with more secure ntlmssp2 challenge/resp */
 GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
-GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
+GLOBAL_EXTERN bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
 GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */

-- 
2.6.3

Several places in the kernel expect to use "on" and "off" for their
boolean signifiers, so add them to strtobool.

Signed-off-by: Kees Cook <redacted>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Daniel Borkmann <daniel@iogearbox.net>
---
 lib/string.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/lib/string.c b/lib/string.c
index 0323c0d5629a..091570708db7 100644
--- a/lib/string.c
+++ b/lib/string.c

@@ -635,12 +635,15 @@ EXPORT_SYMBOL(sysfs_streq);
  * @s: input string
  * @res: result
  *
- * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
- * Otherwise it will return -EINVAL.  Value pointed to by res is
- * updated upon finding a match.
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
+ * pointed to by res is updated upon finding a match.
  */
 int strtobool(const char *s, bool *res)
 {
+	if (!s)
+		return -EINVAL;
+
 	switch (s[0]) {
 	case 'y':
 	case 'Y':

@@ -652,6 +655,21 @@ int strtobool(const char *s, bool *res)
 	case '0':
 		*res = false;
 		break;
+	case 'o':
+	case 'O':
+		switch (s[1]) {
+		case 'n':
+		case 'N':
+			*res = true;
+			break;
+		case 'f':
+		case 'F':
+			*res = false;
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
 	default:
 		return -EINVAL;
 	}

-- 
2.6.3

This changes several users of manual "on"/"off" parsing to use strtobool.

Signed-off-by: Kees Cook <redacted>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
---
 arch/powerpc/kernel/rtasd.c                  | 10 +++-------
 arch/powerpc/platforms/pseries/hotplug-cpu.c | 11 +++--------
 arch/s390/kernel/time.c                      |  8 ++------
 arch/s390/kernel/topology.c                  |  8 +++-----
 arch/x86/kernel/aperture_64.c                | 13 +++----------
 include/linux/tick.h                         |  2 +-
 kernel/time/hrtimer.c                        | 11 +++--------
 kernel/time/tick-sched.c                     | 11 +++--------
 8 files changed, 21 insertions(+), 53 deletions(-)

diff --git a/arch/powerpc/kernel/rtasd.c b/arch/powerpc/kernel/rtasd.c
index 5a2c049c1c61..984e67e91ba3 100644
--- a/arch/powerpc/kernel/rtasd.c
+++ b/arch/powerpc/kernel/rtasd.c

@@ -21,6 +21,7 @@
 #include <linux/cpu.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>

@@ -49,7 +50,7 @@ static unsigned int rtas_error_log_buffer_max;
 static unsigned int event_scan;
 static unsigned int rtas_event_scan_rate;
 
-static int full_rtas_msgs = 0;
+static bool full_rtas_msgs;
 
 /* Stop logging to nvram after first fatal error */
 static int logging_enabled; /* Until we initialize everything,

@@ -592,11 +593,6 @@ __setup("surveillance=", surveillance_setup);
 
 static int __init rtasmsgs_setup(char *str)
 {
-	if (strcmp(str, "on") == 0)
-		full_rtas_msgs = 1;
-	else if (strcmp(str, "off") == 0)
-		full_rtas_msgs = 0;
-
-	return 1;
+	return strtobool(str, &full_rtas_msgs);
 }
 __setup("rtasmsgs=", rtasmsgs_setup);

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 32274f72fe3f..bb333e9fd77a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c

@@ -27,6 +27,7 @@
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
 #include <asm/firmware.h>

@@ -47,20 +48,14 @@ static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;
 
 static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;
 
-static int cede_offline_enabled __read_mostly = 1;
+static bool cede_offline_enabled __read_mostly = true;
 
 /*
  * Enable/disable cede_offline when available.
  */
 static int __init setup_cede_offline(char *str)
 {
-	if (!strcmp(str, "off"))
-		cede_offline_enabled = 0;
-	else if (!strcmp(str, "on"))
-		cede_offline_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return strtobool(str, &cede_offline_enabled);
 }
 
 __setup("cede_offline=", setup_cede_offline);

diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 99f84ac31307..afc7fc9684ba 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c

@@ -1433,7 +1433,7 @@ device_initcall(etr_init_sysfs);
 /*
  * Server Time Protocol (STP) code.
  */
-static int stp_online;
+static bool stp_online;
 static struct stp_sstpi stp_info;
 static void *stp_page;
 

@@ -1444,11 +1444,7 @@ static struct timer_list stp_timer;
 
 static int __init early_parse_stp(char *p)
 {
-	if (strncmp(p, "off", 3) == 0)
-		stp_online = 0;
-	else if (strncmp(p, "on", 2) == 0)
-		stp_online = 1;
-	return 0;
+	return strtobool(p, &stp_online);
 }
 early_param("stp", early_parse_stp);
 

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 40b8102fdadb..10e388216307 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c

@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/cpu.h>
 #include <linux/smp.h>
 #include <linux/mm.h>

@@ -37,7 +38,7 @@ static void set_topology_timer(void);
 static void topology_work_fn(struct work_struct *work);
 static struct sysinfo_15_1_x *tl_info;
 
-static int topology_enabled = 1;
+static bool topology_enabled = true;
 static DECLARE_WORK(topology_work, topology_work_fn);
 
 /*

@@ -444,10 +445,7 @@ static const struct cpumask *cpu_book_mask(int cpu)
 
 static int __init early_parse_topology(char *p)
 {
-	if (strncmp(p, "off", 3))
-		return 0;
-	topology_enabled = 0;
-	return 0;
+	return strtobool(p, &topology_enabled);
 }
 early_param("topology", early_parse_topology);
 

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 6e85f713641d..6608b00a516a 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c

@@ -20,6 +20,7 @@
 #include <linux/pci_ids.h>
 #include <linux/pci.h>
 #include <linux/bitops.h>
+#include <linux/string.h>
 #include <linux/suspend.h>
 #include <asm/e820.h>
 #include <asm/io.h>

@@ -227,19 +228,11 @@ static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
 	return 0;
 }
 
-static int gart_fix_e820 __initdata = 1;
+static bool gart_fix_e820 __initdata = true;
 
 static int __init parse_gart_mem(char *p)
 {
-	if (!p)
-		return -EINVAL;
-
-	if (!strncmp(p, "off", 3))
-		gart_fix_e820 = 0;
-	else if (!strncmp(p, "on", 2))
-		gart_fix_e820 = 1;
-
-	return 0;
+	return strtobool(p, &gart_fix_e820);
 }
 early_param("gart_fix_e820", parse_gart_mem);
 

diff --git a/include/linux/tick.h b/include/linux/tick.h
index 97fd4e543846..0ecdf0e248f4 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h

@@ -98,7 +98,7 @@ static inline void tick_broadcast_exit(void)
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
-extern int tick_nohz_enabled;
+extern bool tick_nohz_enabled;
 extern int tick_nohz_tick_stopped(void);
 extern void tick_nohz_idle_enter(void);
 extern void tick_nohz_idle_exit(void);

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 435b8850dd80..40d82fe4d2a5 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c

@@ -39,6 +39,7 @@
 #include <linux/syscalls.h>
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
+#include <linux/string.h>
 #include <linux/tick.h>
 #include <linux/seq_file.h>
 #include <linux/err.h>

@@ -515,7 +516,7 @@ static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
 /*
  * High resolution timer enabled ?
  */
-static int hrtimer_hres_enabled __read_mostly  = 1;
+static bool hrtimer_hres_enabled __read_mostly  = true;
 unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC;
 EXPORT_SYMBOL_GPL(hrtimer_resolution);
 

@@ -524,13 +525,7 @@ EXPORT_SYMBOL_GPL(hrtimer_resolution);
  */
 static int __init setup_hrtimer_hres(char *str)
 {
-	if (!strcmp(str, "off"))
-		hrtimer_hres_enabled = 0;
-	else if (!strcmp(str, "on"))
-		hrtimer_hres_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return strtobool(str, &hrtimer_hres_enabled);
 }
 
 __setup("highres=", setup_hrtimer_hres);

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9d7a053545f5..bd97702a0760 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c

@@ -19,6 +19,7 @@
 #include <linux/percpu.h>
 #include <linux/profile.h>
 #include <linux/sched.h>
+#include <linux/string.h>
 #include <linux/module.h>
 #include <linux/irq_work.h>
 #include <linux/posix-timers.h>

@@ -387,20 +388,14 @@ void __init tick_nohz_init(void)
 /*
  * NO HZ enabled ?
  */
-int tick_nohz_enabled __read_mostly = 1;
+bool tick_nohz_enabled __read_mostly  = true;
 unsigned long tick_nohz_active  __read_mostly;
 /*
  * Enable / Disable tickless mode
  */
 static int __init setup_tick_nohz(char *str)
 {
-	if (!strcmp(str, "off"))
-		tick_nohz_enabled = 0;
-	else if (!strcmp(str, "on"))
-		tick_nohz_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return strtobool(str, &tick_nohz_enabled);
 }
 
 __setup("nohz=", setup_tick_nohz);

-- 
2.6.3

On Thu, Jan 28, 2016 at 06:17:07AM -0800, Kees Cook wrote:

This changes several users of manual "on"/"off" parsing to use strtobool.

Signed-off-by: Kees Cook <redacted>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
---
 arch/powerpc/kernel/rtasd.c                  | 10 +++-------
 arch/powerpc/platforms/pseries/hotplug-cpu.c | 11 +++--------
 arch/s390/kernel/time.c                      |  8 ++------
 arch/s390/kernel/topology.c                  |  8 +++-----
 arch/x86/kernel/aperture_64.c                | 13 +++----------
 include/linux/tick.h                         |  2 +-
 kernel/time/hrtimer.c                        | 11 +++--------
 kernel/time/tick-sched.c                     | 11 +++--------
 8 files changed, 21 insertions(+), 53 deletions(-)

For the s390 bits:

Acked-by: Heiko Carstens <redacted>

On Thu, 2016-01-28 at 06:17 -0800, Kees Cook wrote:

This changes several users of manual "on"/"off" parsing to use strtobool.

You should probably point out that it's a slight behaviour change for some
users. ie. parameters that previously *only* worked with "on"/"off", can now
also take 0/1/y/n etc.

But I don't think that's a show stopper.

Signed-off-by: Kees Cook <redacted>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
---
 arch/powerpc/kernel/rtasd.c                  | 10 +++-------
 arch/powerpc/platforms/pseries/hotplug-cpu.c | 11 +++--------

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)


cheers

On Thu, Jan 28, 2016 at 4:17 PM, Kees Cook [off-list ref] wrote:

Some callers of strtobool were passing a pointer to unterminated strings.
This fixes the issue and consolidates some logic in cifs.

My comments below.

First of all I don't think currently there is an issue in cifs, since
strbool checks only first character of the input string, or are you
talking about something else?

Can we do strtobool_from_user() instead like kstrto*from_user() and
similar helpers are done?

I would suggest to do a separate patch which just changes a pattern
and thus indentation without changing anything in functionality.

-- 
With Best Regards,
Andy Shevchenko

On Mon, Feb 1, 2016 at 5:17 AM, Andy Shevchenko
[off-list ref] wrote:

On Thu, Jan 28, 2016 at 4:17 PM, Kees Cook [off-list ref] wrote:

quoted

Some callers of strtobool were passing a pointer to unterminated strings.
This fixes the issue and consolidates some logic in cifs.

My comments below.

First of all I don't think currently there is an issue in cifs, since
strbool checks only first character of the input string, or are you
talking about something else?

Right, no, this is a fix before extending strtobool to parse the
second character in the string (for handling "on" and "off").

quoted

diff --git a/drivers/net/wireless/marvell/mwifiex/debugfs.c b/drivers/net/wireless/marvell/mwifiex/debugfs.c
index 0b9c580af988..76af60899c69 100644
--- a/drivers/net/wireless/marvell/mwifiex/debugfs.c
+++ b/drivers/net/wireless/marvell/mwifiex/debugfs.c

@@ -880,13 +880,13 @@ mwifiex_reset_write(struct file *file,
 {
        struct mwifiex_private *priv = file->private_data;
        struct mwifiex_adapter *adapter = priv->adapter;
-       char cmd;
+       char cmd[2] = { '\0' };
        bool result;

-       if (copy_from_user(&cmd, ubuf, sizeof(cmd)))
+       if (copy_from_user(cmd, ubuf, sizeof(char)))
                return -EFAULT;

-       if (strtobool(&cmd, &result))
+       if (strtobool(cmd, &result))
                return -EINVAL;

Can we do strtobool_from_user() instead like kstrto*from_user() and
similar helpers are done?

Yeah, that might clean this up a bit more. I will add it.

quoted

        if (!result)

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 50b268483302..2f7ffcc9e364 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c

@@ -251,11 +251,29 @@ static const struct file_operations cifs_debug_data_proc_fops = {
        .release        = single_release,
 };

+static int get_user_bool(const char __user *buffer, bool *store)
+{
+       char c[2] = { '\0' };
+       bool bv;
+       int rc;
+
+       rc = get_user(c[0], buffer);
+       if (rc)
+               return rc;
+
+       rc = strtobool(c, &bv);
+       if (rc)
+               return rc;
+
+       *store = bv;
+
+       return 0;
+}
+
 #ifdef CONFIG_CIFS_STATS
 static ssize_t cifs_stats_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
 {
-       char c;
        bool bv;
        int rc;
        struct list_head *tmp1, *tmp2, *tmp3;

@@ -263,34 +281,32 @@ static ssize_t cifs_stats_proc_write(struct file *file,
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;

-       rc = get_user(c, buffer);
+       rc = get_user_bool(buffer, &bv);
        if (rc)
                return rc;

-       if (strtobool(&c, &bv) == 0) {
 #ifdef CONFIG_CIFS_STATS2

I would suggest to do a separate patch which just changes a pattern
and thus indentation without changing anything in functionality.

Okay, noted.

quoted

-               atomic_set(&totBufAllocCount, 0);
-               atomic_set(&totSmBufAllocCount, 0);
+       atomic_set(&totBufAllocCount, 0);
+       atomic_set(&totSmBufAllocCount, 0);
 #endif /* CONFIG_CIFS_STATS2 */
-               spin_lock(&cifs_tcp_ses_lock);
-               list_for_each(tmp1, &cifs_tcp_ses_list) {
-                       server = list_entry(tmp1, struct TCP_Server_Info,
-                                           tcp_ses_list);
-                       list_for_each(tmp2, &server->smb_ses_list) {
-                               ses = list_entry(tmp2, struct cifs_ses,
-                                                smb_ses_list);
-                               list_for_each(tmp3, &ses->tcon_list) {
-                                       tcon = list_entry(tmp3,
-                                                         struct cifs_tcon,
-                                                         tcon_list);
-                                       atomic_set(&tcon->num_smbs_sent, 0);
-                                       if (server->ops->clear_stats)
-                                               server->ops->clear_stats(tcon);
-                               }
+       spin_lock(&cifs_tcp_ses_lock);
+       list_for_each(tmp1, &cifs_tcp_ses_list) {
+               server = list_entry(tmp1, struct TCP_Server_Info,
+                                   tcp_ses_list);
+               list_for_each(tmp2, &server->smb_ses_list) {
+                       ses = list_entry(tmp2, struct cifs_ses,
+                                        smb_ses_list);
+                       list_for_each(tmp3, &ses->tcon_list) {
+                               tcon = list_entry(tmp3,
+                                                 struct cifs_tcon,
+                                                 tcon_list);
+                               atomic_set(&tcon->num_smbs_sent, 0);
+                               if (server->ops->clear_stats)
+                                       server->ops->clear_stats(tcon);
                        }
                }
-               spin_unlock(&cifs_tcp_ses_lock);
        }
+       spin_unlock(&cifs_tcp_ses_lock);

        return count;
 }

@@ -433,17 +449,17 @@ static int cifsFYI_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *ppos)
 {
-       char c;
+       char c[2] = { '\0' };
        bool bv;
        int rc;

-       rc = get_user(c, buffer);
+       rc = get_user(c[0], buffer);
        if (rc)
                return rc;
-       if (strtobool(&c, &bv) == 0)
+       if (strtobool(c, &bv) == 0)
                cifsFYI = bv;
-       else if ((c > '1') && (c <= '9'))
-               cifsFYI = (int) (c - '0'); /* see cifs_debug.h for meanings */
+       else if ((c[0] > '1') && (c[0] <= '9'))
+               cifsFYI = (int) (c[0] - '0'); /* see cifs_debug.h for meanings */

        return count;
 }

@@ -471,20 +487,12 @@ static int cifs_linux_ext_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_linux_ext_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
 {
-       char c;
-       bool bv;
        int rc;

-       rc = get_user(c, buffer);
+       rc = get_user_bool(buffer, &linuxExtEnabled);
        if (rc)
                return rc;

-       rc = strtobool(&c, &bv);
-       if (rc)
-               return rc;
-
-       linuxExtEnabled = bv;
-
        return count;
 }

@@ -511,20 +519,12 @@ static int cifs_lookup_cache_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_lookup_cache_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
 {
-       char c;
-       bool bv;
        int rc;

-       rc = get_user(c, buffer);
+       rc = get_user_bool(buffer, &lookupCacheEnabled);
        if (rc)
                return rc;

-       rc = strtobool(&c, &bv);
-       if (rc)
-               return rc;
-
-       lookupCacheEnabled = bv;
-
        return count;
 }

@@ -551,20 +551,12 @@ static int traceSMB_proc_open(struct inode *inode, struct file *file)
 static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *ppos)
 {
-       char c;
-       bool bv;
        int rc;

-       rc = get_user(c, buffer);
+       rc = get_user_bool(buffer, &traceSMB);
        if (rc)
                return rc;

-       rc = strtobool(&c, &bv);
-       if (rc)
-               return rc;
-
-       traceSMB = bv;
-
        return count;
 }

@@ -622,7 +614,7 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
        int rc;
        unsigned int flags;
        char flags_string[12];
-       char c;
+       char c[2] = { '\0' };
        bool bv;

        if ((count < 1) || (count > 11))

@@ -635,11 +627,11 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,

        if (count < 3) {
                /* single char or single char followed by null */
-               c = flags_string[0];
-               if (strtobool(&c, &bv) == 0) {
+               c[0] = flags_string[0];
+               if (strtobool(c, &bv) == 0) {
                        global_secflags = bv ? CIFSSEC_MAX : CIFSSEC_DEF;
                        return count;
-               } else if (!isdigit(c)) {
+               } else if (!isdigit(c[0])) {
                        cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
                                        flags_string);
                        return -EINVAL;

diff --git a/fs/cifs/cifs_debug.h b/fs/cifs/cifs_debug.h
index 66cf0f9fff89..c611ca2339d7 100644
--- a/fs/cifs/cifs_debug.h
+++ b/fs/cifs/cifs_debug.h

@@ -25,7 +25,7 @@
 void cifs_dump_mem(char *label, void *data, int length);
 void cifs_dump_detail(void *);
 void cifs_dump_mids(struct TCP_Server_Info *);
-extern int traceSMB;           /* flag which enables the function below */
+extern bool traceSMB;          /* flag which enables the function below */
 void dump_smb(void *, int);
 #define CIFS_INFO      0x01
 #define CIFS_RC                0x02

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index c48ca13673e3..931b446f2a44 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c

@@ -54,10 +54,10 @@
 #endif

 int cifsFYI = 0;
-int traceSMB = 0;
+bool traceSMB;
 bool enable_oplocks = true;
-unsigned int linuxExtEnabled = 1;
-unsigned int lookupCacheEnabled = 1;
+bool linuxExtEnabled = true;
+bool lookupCacheEnabled = true;
 unsigned int global_secflags = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a25b2513f146..d21da9f05bae 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h

@@ -1596,11 +1596,11 @@ GLOBAL_EXTERN atomic_t midCount;

 /* Misc globals */
 GLOBAL_EXTERN bool enable_oplocks; /* enable or disable oplocks */
-GLOBAL_EXTERN unsigned int lookupCacheEnabled;
+GLOBAL_EXTERN bool lookupCacheEnabled;
 GLOBAL_EXTERN unsigned int global_secflags;    /* if on, session setup sent
                                with more secure ntlmssp2 challenge/resp */
 GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
-GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
+GLOBAL_EXTERN bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
 GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
--

2.6.3

--
With Best Regards,
Andy Shevchenko

Thanks for the review!

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security